A Lightweight Design of Tree-shaped Support Structures for SLM Additive Manufacturing

Support structures are used to hold the overhangs of the models and dissipate process heat in the Selective Laser Melting (SLM) processes. However, the support structures are sacrificed afterwards in order to obtain the target 3D models. Therefore, to save both printing time and materials, minimizing the volume of support structures is an effective means. Tree-shaped structure is an effective design for the lightweight design of the support structures. Although existing commercial software such as Autodesk Meshmixer have provided the function of generating tree-supports by manually setting the geometric parameters, the problem of designing a stable tree-support of minimum volume to reduce the material and printing time without sacrificing the printing quality for 3D-printed metal models has not been addressed properly. We propose a combination of an experimental method and a volume minimization framework using a strategy of improved Particle Swarm Optimization (PSO). We carried out a set of experiments to compare our method with traditional “point supports” and the tree-supports module of Autodesk Meshmixer. Simulation and experimental results reveal that our approach is effective in reducing support volume and printing time.